JP5815304B2 - Optical thin film forming paint and optical thin film - Google Patents

Description

The present invention relates to a coating for forming an optical thin film and an optical thin film.
More specifically, the present invention relates to an optical thin film-forming coating material and an optical thin film that have a high refractive index, excellent transparency, haze, and hardness, and excellent optical thin film formability.

Conventionally, in a liquid crystal display device, a prism layer having a high refractive index is provided in order to improve the brightness of a display image, increase the brightness, and increase the definition by enhancing the light condensing property and light transmittance of the backlight. (See Figure 1)
In a light emitting diode (LED), the semiconductor element is sealed with a transparent sealing material such as an epoxy resin or a silicone resin in order to protect the semiconductor element.

  However, there is a problem that energy emitted from the LED increases as the wavelength of the LED becomes shorter and the luminance increases, and in some cases, heat is stored and the sealing resin is yellowed to lower the luminance of the LED.

Moreover, since the refractive index of the sealing material is low, there is a problem that light emitted from the LED is reflected by the sealing material and the light transmittance is lowered, and energy efficiency is lowered.
For this reason, a composition in which silicone resin is blended with surface-modified zirconia particles having a particle diameter of 1 to 20 nm is proposed as a sealing material that has excellent thermal stability, improved refractive index, and improved light transmittance. Has been. (Patent Document 1: JP 2009-173757 A)

  However, in order to improve the dispersibility of zirconia particles in silicone resin, primary surface modification and secondary surface modification are necessary, and in order to eliminate residual OH group, tertiary surface modification with alkylsilazane surface treatment agent is necessary. Therefore, in addition to low productivity, a large amount of surface modifier is required, and these surface treatment agents have a refractive index of around 1.4. In addition, the refractive index of the cured resin (sealing material) using this is not necessarily high, and thus there has been a limit to improving the light transmittance.

It is known that particles are surface-treated with a silane coupling agent in order to improve the dispersibility of the particles to prevent aggregation and improve the stability of the coating liquid. A resin is coated by a graft polymerization method or the like to increase the affinity with a matrix component or a dispersion medium. (JP-A-3-163172 (Patent Document 2), JP-A-6-336558 (Patent Document 3), JP-A-6-49251 (Patent Document 4), JP-A 2000-143230 (Patent Document) 5))
JP-A-7-118123 (Patent Document 6) and JP-A-2003-63932 (Patent Document 7) disclose cosmetic powders coated with a resin.

  The applicant of the present application adds an acrylic resin to an organic solvent dispersion in which ethers, esters, and ketones of metal oxide particles that have been heat-treated in advance are used as a dispersion medium, and then performs mechanochemical treatment to obtain individual metal oxides. It is disclosed that resin particles can be uniformly coated on the product particles, and a high-concentration resin-coated metal oxide particle dispersion liquid having an organic solvent as a dispersion medium and a solid content concentration of up to about 50% by weight can be obtained. JP 2010-077409 (Patent Document 8)

  Further, JP 2007-238759 A (Patent Document 9) discloses a first step of producing a first mixture containing at least inorganic fine particles such as alumina, a first thermoplastic resin, and a first organic solvent. A method for producing a resin composition comprising a second step in which a mechanical load is applied thereto to cause peptization of inorganic fine particles and then a third step in which only the solvent is distilled off is disclosed. This resin composition is intended for resination of glass members including window shields of automobiles, etc., and at this time, it has transparency, reduces expansion with respect to heat, and obtains a resin composition having high bending rigidity. For this reason, acicular alumina particles having a small particle diameter and a high aspect ratio are recommended.

JP 2009-173757 A Japanese Patent Laid-Open No. 3-163172 JP-A-6-336558 JP-A-6-49251 JP 2000-143230 A JP 7-118123 A JP 2003-63932 A JP 2010-077409 A JP 2007-238759 A

  Under such circumstances, there is a demand for a sealing material and an optical thin film that have higher light transmittance and excellent thermal stability. In addition to the transparent film having a constant film thickness, the optical thin film is formed with a prism shape, a convex structure on the upper surface (convex lens shape) or an uneven structure (wave structure), and a film having a number of convex structures on the upper surface. Thus, it has been desired to have a function of improving the light collecting property.

  Based on the background as described above, the present inventors diligently investigated optical thin films such as a sealing material and a prism sheet that have high light transmittance, excellent light condensing properties, and excellent thermal stability. As a result, when using a paint comprising a (meth) acrylate resin having a small molecular weight and not having a fluorene skeleton, a (meth) acrylate resin having a fluorene skeleton and resin-coated zirconia fine particles, the moldability is excellent, and the refractive index is high. The present invention has been completed by finding that an optical thin film excellent in transparency, light transmittance, light condensing property and the like can be formed.

The configuration of the present invention is as follows.
[1] a (meth) acrylate resin (A) having a fluorene skeleton having a weight average molecular weight of 86 to 3,000,
(Meth) acrylate resin (B) having a fluorene skeleton,
A coating for forming an optical thin film comprising resin-coated inorganic oxide fine particles (C) having an average particle diameter in the range of 5 to 50 nm.
[2] The coating composition for forming an optical thin film according to [1], wherein the (meth) acrylate resin (A) having no fluorene skeleton has an aromatic ring and / or an epoxy ring.
[3] The optical fiber according to [1], wherein the resin-coated inorganic oxide fine particles (C) are coated with a (meth) acrylate resin, and the (meth) acrylate resin has an aromatic ring. Thin film coating.

[4] A (meth) acrylate resin having a concentration of (meth) acrylate resin (A) having no fluorene skeleton (C _R ) in the range of 20 to 60% by weight as a solid content and having the fluorene skeleton. The concentration (C _F ) of (B) is in the range of 10 to 60 wt% as the solid content, the concentration of the resin-coated inorganic oxide fine particles (C) is in the range of 20 to 70 wt% as the solid content, and organic The coating composition for forming an optical thin film according to [1] to [3], wherein the concentration of the solvent is 1000 ppm or less.
[5] Concentration ratio between the concentration (C _R ) of the (meth) acrylate resin (A) not having the fluorene skeleton and the concentration (C _F ) of the (meth) acrylate resin (B) having the fluorene skeleton ( C _F ) / (C _R ) [1] to [4] coating for optical thin film formation in the range of 0.2 to 3.0
[6] The coating composition for forming an optical thin film according to [1] to [5], wherein the resin-coated inorganic oxide fine particles (C) have a refractive index in the range of 1.7 to 2.1.

[7] The coating for forming an optical thin film according to [1] to [6], wherein the inorganic oxide fine particles are zirconia-based fine particles.
[8] The coating composition for forming an optical thin film according to [1] to [7], wherein the viscosity (η) is in the range of 10 to 8,000 Pa · s.
[9] The coating composition for forming an optical thin film according to [1] to [8], having a refractive index in the range of 1.5 to 1.8.
[10] An optical thin film formed using the optical thin film forming paint according to [1] to [9].
[11] The optical thin film according to [10], which has a light transmittance of 80% or more.
[12] The optical thin film according to [10] or [11], having a refractive index in the range of 1.6 to 1.8.
[13] The optical thin film according to [9] to [12], which has a wave shape, a prism shape, a sawtooth shape, a convex lens shape, and a concave lens shape.

  According to the present invention, an optical thin film having a high refractive index and excellent transparency and light transmittance can be formed. Moreover, the optical thin film excellent in condensing property etc. can be formed by making an optical thin film into a prism structure, or providing uneven | corrugated shape (wave-like liquid).

The schematic of one application example of the optical thin film of this invention is shown. The schematic of another application example of the optical thin film of this invention is shown. The schematic of another application example of the optical thin film of this invention is shown.

Hereinafter, the optical thin film-forming paint according to the present invention will be described first.
[Paint for optical thin film formation]
The coating composition for forming an optical thin film according to the present invention includes a (meth) acrylate resin (A) having a fluorene skeleton having a weight average molecular weight of 100 to 3,000, and a (meth) acrylate resin having a fluorene skeleton. (B) and resin-coated inorganic oxide fine particles (C) having an average particle diameter in the range of 5 to 50 nm.
In addition, the (meth) acrylate resin in this invention is the meaning containing the monomer (monomer) and oligomer of an acrylate thru | or methacrylate.

(Meth) acrylate resin without fluorene skeleton (A)
The (meth) acrylate resin (A) having no fluorene skeleton used in the present invention has an acrylate structure (acrylic ester) or a methacrylate structure (methacrylic ester), and is usually a single monomer such as a monomer. However, it may be an oligomer that has undergone polymerization to some extent.

  Examples of the (meth) acrylate resin (A) having no fluorene skeleton include methyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, lauryl methacrylate, n-stearyl methacrylate, n-butoxyethyl methacrylate, butoxyethyl acrylate, butoxyethylene glycol methacrylate, butoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, methoxypolyethylene glycol acrylate, phenoxyethyl methacrylate, phenoxyethyl acrylate, 2-hydroxyethyl methacrylate, 2 -Hydroxyethyl acrylate, 2- Hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxybutyl acrylate, glycidyl methacrylate, trimethylolpropane trimethacrylate, methoxytriethylene glycol dimethacrylate , Ditrimethylolpropane tetraacrylate, trimethylolpropane trimethacrylate, methoxytriethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol diglycidyl ether acrylate, polyethylene glycol diglycidyl ether acrylate, dipropylene glycol diglycidyl Ether acrylate, poly Lopylene glycol diglycidyl ether acrylate, 1,6-hexanediol diglycidyl ether acrylate, 2-ethylhexyl glycidyl ether acrylate, pentaerythritol polyglycidyl ether acrylate, neopentyl glycol diglycidyl ether acrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A methacrylate, ethoxylated cyclohexanedimethanol di (meth) acrylate, propoxylated bisphenol A diacrylate, propoxylated ethoxylated bisphenol A diacrylate, propoxylated bisphenol A diglycidyl ether acrylate, O-phthalic acid diglycidyl ether acrylate, cyclohexane di Methanol diglycidyl ether Acrylate, pt-butylphenylglycidyl ether acrylate, O-phenylphenol glycidyl ether acrylate, 2-hydroxy-3-phenoxypropyl acrylate, bisphenol A type epoxy acrylate, phenol novolac type epoxy acrylate, cresol novolac type epoxy acrylate, penta Examples include erythritol triacrylate, trimethylolpropane triacrylate, tetramethylol methane triacrylate, tetramethylol methane tetraacrylate, tetramethylol methane triacrylate, tetramethylol methane tetraacrylate, and mixtures thereof. Among these, those having at least one aromatic ring are preferable from the viewpoint of refractive index and transparency. Moreover, what has an epoxy ring from the point of sclerosis | hardenability and durability is also suitable. Accordingly, the (meth) acrylate resin (A) having no fluorene skeleton is more preferably one having an aromatic ring and / or an epoxy ring.

  The weight average molecular weight of the (meth) acrylate-based resin (A) having no fluorene skeleton is not particularly limited, and is usually preferably in the range of 86 to 3,000, more preferably 200 to 2,000. .

  When the (meth) acrylate-based resin (A) that does not have a fluorene skeleton has a low weight average molecular weight, the resulting thin film has a low refractive index and low hardness, resulting in insufficient function as a high refractive index film. There is.

  If the weight average molecular weight of the (meth) acrylate-based resin (A) that does not have a fluorene skeleton is too large, depending on the amount of the resin, the viscosity of the coating for forming an optical thin film becomes too high, resulting in the formation of an optical thin film. May be insufficient.

The concentration (C _R ) as a solid content of the (meth) acrylate resin (A) having no fluorene skeleton in the coating for forming an optical thin film is in the range of 10 to 60% by weight, more preferably 12 to 50% by weight. It is preferable. When C _R is too small, the formation of the optical thin film becomes too high viscosity of the optical thin film-forming coating material, the appearance of the formed coating film becomes insufficient. When C _R is too large, while the acrylate resin (B) is reduced with a fluorene skeleton, the refractive index of the coating film formed by an optical thin film-forming coating material is low, the insufficient function as a high refractive index film There is a case.

(Meth) acrylate resin with fluorene skeleton (B)
The (meth) acrylate resin (B) having a fluorene skeleton has a fluorene skeleton.

（メタ）アクリレート系樹脂(B)であれば特に制限はなく、アクリレート構造（アクリル酸エステル）ないしメタクリレート構造（メタクリル酸エステル）を有するものであり、通常モノマーのような単量体が使用されるが、ある程度重合が進んだオリゴマーであってもよい。

The (meth) acrylate resin (B) is not particularly limited and has an acrylate structure (acrylate ester) or a methacrylate structure (methacrylate ester), and a monomer such as a monomer is usually used. However, it may be an oligomer that has been polymerized to some extent.

  Examples of such (meth) acrylate resins having a fluorene skeleton include bisphenol fluorene (meth) acrylate, biscresol fluorene (meth) acrylate, bisphenoxyethanol fluorene (meth) acrylate, bisaminofernifluorene (meth) acrylate, bis Aminopropylfluorene (meth) acrylate, bisaminomethylfluorene (meth) acrylate, bishydroxymethylpropylfluorene, bishydroxyphenylfluorene, bishydroxyethoxyfluorene, dioctylfluorene, dimethylfluorene, bisacryloyloxyethoxyphenylfluorene, fluorene Acrylate, fluorene methacrylate, full orange acrylate, full orange methacrylate And the like.

  When the (meth) acrylate-based resin (B) having such a fluorene skeleton is included, it is possible to obtain a high refractive index paint having a low viscosity and excellent moldability, and the obtained optical thin film has a high refractive index. , Excellent in transparency and light collection.

  When such a (meth) acrylate resin (B) having a fluorene skeleton is combined with the (meth) acrylate resin (A), the viscosity of the (meth) acrylate resin (B) having a fluorene skeleton alone is low. Although the moldability is high, the transparency increases when combined with the (meth) acrylate resin (A). Further, when combined with the (meth) acrylate resin (A) containing an aromatic ring, the refractive index does not decrease, and the light condensing property is excellent when irregularities are formed.

The concentration (C _F ) as a solid content of the (meth) acrylate-based resin (B) having the fluorene skeleton in the coating for forming an optical thin film is in the range of 10 to 60% by weight, more preferably 20 to 50% by weight. Is preferred. When C _F is low, depending on the content of the resin-coated inorganic oxide fine particles (C) described later, it may be difficult to obtain a coating for forming an optical thin film and an optical thin film having a desired refractive index. Even if C _F is too high, the refractive index of the paint and the optical thin film becomes high, but the viscosity of the paint for forming the optical thin film becomes too high, and the formability of the optical thin film and the appearance of the formed optical thin film become insufficient. There is a case.

Concentration (C _R ) as a solid content of the (meth) acrylate resin (A) having no fluorene skeleton and a concentration (C _F ) as a solid content of the (meth) acrylate resin (B) having a fluorene skeleton The ratio C _F / C _R is preferably in the range of 0.2 to 3, more preferably 0.5 to 2.0. With this ratio, the refractive index is high and the moldability can be kept high. If (C _F ) / (C _R ) is low, the refractive index will be low, and it may be difficult to obtain an optical thin film-forming paint or optical thin film having a desired refractive index. In some cases, the refractive index becomes insufficient and sufficient light condensing performance cannot be obtained. If (C _F ) / (C _R ) is too high, the refractive index of the paint and the optical thin film will be high, but the viscosity of the paint for forming an optical thin film will be too high. May be insufficient.

Resin-coated inorganic oxide fine particles (C)
In the resin-coated inorganic oxide fine particles (C) used in the present invention, the inorganic oxide fine particles are coated with a resin. By containing such fine particles (C), a coating for forming an optical thin film excellent in dispersibility, stability, and moldability can be obtained. In addition, an optical thin film having excellent film strength and hardness, excellent transparency, high refractive index, and excellent light collecting properties can be obtained.

(i) Coating resin As the coating resin, a (meth) acrylate resin is preferable, and a (meth) acrylate resin having an aromatic ring is particularly preferable.

  Such a coating resin may be the same as or different from the (meth) acrylate resin (A) having no fluorene skeleton and the (meth) acrylate resin (B) having a fluorene skeleton.

  When a (meth) acrylate resin having an aromatic ring is used, it is possible to uniformly coat individual particles, and resin-coated inorganic oxide fine particles (C) and (meth) acrylate resins (A) and (B ) Can be dispersed uniformly. Accordingly, a coating for forming an optical thin film excellent in stability in which resin-coated inorganic oxide fine particles (C) are highly dispersed is obtained, and a curing agent is added to the coating, applied, and cured without drying. Forms an optical thin film with high refractive index, high transparency, high transparency, haze, hardness, scratch resistance, and excellent light-collecting properties because the solvent does not scatter and the film thickness at the time of coating is unchanged be able to.

  The (meth) acrylate resin for coating the inorganic oxide fine particles is preferably a (meth) acrylate resin having at least one functional group selected from a hydroxyl group, an amino group, a carbonyl group, a carboxyl group, and a sulfo group. .

  Those having such a functional group have high affinity with the inorganic oxide fine particles, and are strongly adsorbed on the surface of the particles and bonded in some cases, so that a dense and uniform resin coating layer can be formed at the time of preparation.

  Examples of (meth) acrylate resins used in the present invention include ethoxylated bisphenol A diacrylate, propoxylated bisphenol A diacrylate, propoxylated ethoxylated bisphenol A diacrylate, propoxylated bisphenol A diglycidyl ether acrylate, and O-phthalate. Acid diglycidyl ether acrylate, pt-butylphenyl glycidyl ether acrylate, 9.9-bis-4-acryloyloxyethoxyphenyl fluorene, bisphenol A diglycidyl ether (meth) acrylic acid adduct, O-phenylphenol glycidyl Ether acrylate, 2-hydroxy-3-phenoxypropyl acrylate, bisphenol A type epoxy acrylate, phenol novolac type epoxy acrylate , Cresol novolak epoxy acrylate, mixtures and of these (meth) acrylate resins such as carboxylic acid anhydride-modified epoxy acrylate.

(ii) Inorganic oxide fine particles Inorganic oxide fine particles used in the present invention include, for example, zirconium oxide, aluminum oxide, antimony oxide, cerium oxide, zinc oxide, tin oxide and the like, and composite oxides containing these as main components, these Can be mentioned.

  Among these, zirconium oxide fine particles and composite oxide fine particles mainly composed of zirconium oxide can be preferably used because they have a high refractive index and are chemically and thermally stable without having photoactivity.

The average particle size (primary particle size) of the inorganic oxide fine particles is preferably in the range of about 5 to 50 nm, more preferably 8 to 40 nm. Those within this range are suitable for optical applications.
If the average particle size is small, the crystallinity is low and the refractive index is low. In addition, the resin-coated inorganic oxide fine particles (C) may be agglomerated, which makes the resin coating non-uniform. , Dispersibility may be insufficient. If the average particle size is large, the final resin-coated inorganic oxide fine particles (C) are also large, and the transparency, light transmittance, haze and scratch resistance of the final optical thin film may be insufficient. .

The resin-coated inorganic oxide fine particles (C) preferably have a refractive index in the range of 1.70 to 2.10, preferably 1.70 to 2.00.
The refractive index of the particles used in the present invention was measured by the following method using Series A and AA manufactured by CARGILL as the standard refractive liquid.
(1) The inorganic oxide fine particles or the resin-coated inorganic oxide fine particle dispersion is taken in an evaporator and the dispersion medium is evaporated.
(2) This is dried at 80 ° C. for 12 hours to obtain a powder.
(3) A standard refraction liquid having a known refractive index is dropped on a glass plate of a few drops, and the above powder is mixed therewith.
(4) The operation of (3) above is performed with various standard refractive liquids, and the refractive index of the standard refractive liquid when the mixed liquid becomes transparent is the refractive index of the inorganic oxide fine particles or resin-coated inorganic oxide fine particles. To do.

  The weight ratio (particle / resin) between the inorganic oxide fine particles and the coating resin in the resin-coated inorganic oxide fine particles (C) is 97/3 to 20/80, more preferably 85/15 to 50/50, particularly 70/30 to Preferably it is in the range of 50/50.

  If the proportion of the inorganic oxide fine particles is too large, although depending on the particle diameter, the inorganic oxide fine particles may not be coated completely and uniformly, and an optical thin film-forming coating material excellent in dispersibility, stability and moldability can be obtained. It may not be obtained. On the other hand, if there is too much coating resin, the refractive index of the coating for forming an optical thin film and the optical thin film may be insufficient, and the light condensing performance may be insufficient.

The concentration of the resin-coated inorganic oxide fine particles (C) in the coating for forming an optical thin film is preferably 10 to 80% by weight, more preferably 20 to 70% by weight as a solid content.
If the concentration of the resin-coated inorganic oxide fine particles (C) in the coating for forming an optical thin film is low, the refractive index of the coating for forming an optical thin film and the optical thin film may be insufficient, and the light condensing property may be insufficient.

If the concentration of the resin-coated inorganic oxide fine particles (C) in the coating for forming an optical thin film is too high, the refractive index of the coating for forming an optical thin film and the optical thin film is increased, but the transparency and light transmittance of the optical thin film are poor. May be sufficient.
The average particle diameter of the resin-coated inorganic oxide fine particles is preferably in the range of 5 to 50 nm, more preferably 8 to 40 nm. Those within this range are suitable for optical applications.

Production Method of Resin-Coated Inorganic Oxide Fine Particles (C) The above-mentioned resin-coated inorganic oxide fine particles (C) can be produced, for example, by the following method, but is not limited to the following method.

  A preferred method for producing the resin-coated inorganic oxide fine particles (C) used in the present invention has been described above as inorganic oxide particles, an organic solvent, and a coating resin that have been heat-treated in an average particle diameter range of 5 nm to 100 μm ( A mechanochemical treatment of a mixture of (meth) acrylate resins.

(i) Inorganic oxide particles As the inorganic oxide particles, the types of particles described above are used.
In the present invention, zirconium oxide particles and composite oxide particles mainly containing zirconium oxide are preferable. Among them, zirconium oxide particles have a high refractive index, and when mechanochemical treatment is performed on particles with high crystallinity that have been heat-treated in advance, the surface of the particles can be uniformly coated with a resin and does not have a fluorene skeleton. Resin-coated inorganic oxide fine particles (C) excellent in dispersibility and dispersion stability in the acrylate resin (A) and the (meth) acrylate resin (B) having a fluorene skeleton can be obtained.

The average particle diameter of the inorganic oxide particles is preferably about 5 nm to 100 μm, more preferably about 300 nm to 50 μm.
If the average particle size of the inorganic oxide particles is small, the cleaving of the particles due to the mechanochemical treatment will not occur substantially, or the resin coating will be insufficient, and even if the resin coating can be achieved, it is agglomerated, dispersibility, stability May be insufficient. If the average particle diameter of the inorganic oxide particles is large, the pulverization or pulverization efficiency of the inorganic oxide particles will be reduced, or pulverization will be difficult, and the average particle diameter of the resulting resin-coated inorganic oxide fine particles (C) will be large. The stability of the optical thin film-forming paint using this may become insufficient. Then, the transparency, haze, light transmittance, hardness, scratch resistance, light condensing property, etc. of the optical thin film using the coating for forming an optical thin film may be insufficient.

In addition, when the average particle diameter of the inorganic oxide particle to be used is large, you may make it a predetermined | prescribed average particle diameter by grinding | pulverization and agglomeration as needed.
The average particle diameter of the inorganic oxide particles used in the present invention is not particularly limited as long as it is in the above range, and may be primary particles or secondary particles that are aggregates of primary particles.

The inorganic oxide particles to be used are obtained by spray drying, and the average particle diameter is preferably in the range of 1 to 100 μm, more preferably 2 to 50 μm.
Such inorganic oxide particles are obtained by spray-drying an aqueous dispersion of inorganic oxide particles (including primary particles and secondary particles) having an average particle diameter in the range of 5 nm to approximately 10 μm by a conventional method. .

  When such spray-dried inorganic oxide particles are used, they are easily dispersed in the organic dispersion medium to be described later, and do not thicken at this time, and even when a coating resin is added, it is uniform without thickening. Then, it is easily loosened during mechanochemical treatment, and the inorganic oxide particles can be uniformly coated with the resin.

In the present invention, the average primary particle diameter is determined by taking a transmission electron micrograph (TEM) of the particles, measuring the particle diameter of 100 particles, and obtaining the average value.
Moreover, when the inorganic oxide particle used for a raw material is an aggregated particle (secondary particle), it can obtain | require with the dynamic light-scattering method "micro track particle size distribution measuring apparatus".

The inorganic oxide particles are preferably preliminarily heat-treated at 100 to 800 ° C., more preferably 105 to 500 ° C.
When preparing the inorganic oxide particles, if there is already a heating history in the above temperature range, it is not necessary to perform a separate heat treatment. In addition, even if there is a heating history in the temperature range, if there is a water dispersion history after that, it is preferable to perform heat treatment.

  By such heat treatment, the resin coating amount can be increased and uniformly coated, and as a result, the stability of the resulting resin-coated inorganic oxide particles and the optical thin film forming paint using the same can be enhanced. The reason for this is not clear, but the heat treatment removes the adhering water and increases the activity of the surface of the inorganic oxide particles, which increases the adsorption amount of the coating resin, and binds the inorganic oxide particles to the resin. Can be promoted.

  If the heat treatment temperature is too low, the surface of the inorganic oxide particles may be inactive due to residual water remaining, etc., or the resin adsorption and bonding between the particles and the resin will be insufficient, resulting in insufficient resin coating. In some cases, the stability and moldability of the resulting coating for forming an optical thin film may be insufficient.

  In addition, even if the heat treatment temperature is too high, the inorganic oxide particles are excessively aggregated, or depending on the type of inorganic oxide particles, sintered, and the affinity, adsorbability, and binding properties with the coating resin are greatly reduced. The stability and moldability of the resulting optical thin film-forming paint may be insufficient.

  As a result, the transparency, haze, light condensing property, hardness, scratch resistance, etc. of the obtained optical thin film may be insufficient.

(ii) Organic solvent As the organic solvent, a conventionally known organic solvent can be used.
For example, alcohols such as methanol, ethanol, propanol, 2-propanol (IPA), butanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol; glycols such as ethylene glycol and hexylene glycol; diethyl ether, ethylene glycol Ethers such as monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; propyl acetate, isobutyl acetate , Butyl acetate, isopentyl acetate, pentyl acetate, 3-methyl acetate Esters such as xylbutyl, 2-ethylbutyl acetate, cyclohexyl acetate, ethylene glycol monoacetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, butyl methyl ketone, cyclohexanone, methyl cyclohexanone, dipropyl ketone, methyl pentyl ketone, diisobutyl ketone, isophorone, Ketones such as acetylacetone and acetoacetate; toluene, xylene and the like.

Among them, the ethers, esters, and ketones have good resin coating efficiency, the resulting resin-coated inorganic oxide fine particles (C) have few aggregated particles, are excellent in dispersibility, and are stable without sedimentation. preferable.
In particular, ethers can be suitably used because inorganic oxide particles hardly aggregate in mechanochemical treatment and can be uniformly coated with a resin.

(iii) Coating resin As the coating resin, the (meth) acrylate resin described above is preferably used.
When a (meth) acrylate-based resin having an aromatic ring is used, a coating for forming an optical thin film with better dispersibility, low viscosity, and excellent stability and moldability can be obtained.

(iv) Mechanochemical treatment The inorganic oxide particles and the coating resin are mixed so that the final range is obtained.
The total solid concentration of the inorganic oxide particles and the coating resin during the mechanochemical treatment is preferably in the range of 1 to 50% by weight, more preferably 2 to 45% by weight. If the total solid content is too low, it may be difficult to treat all particles uniformly or may take a long time, and the resin coating may become non-uniform. Dispersibility of the resulting coating for forming an optical thin film In some cases, the stability becomes insufficient, and the obtained optical thin film also has low transparency, high haze, and insufficient light collecting properties.

  If the total solid concentration is too high, depending on the type of inorganic oxide particles, organic solvent, and coating resin, the viscosity may suddenly increase or the particles may agglomerate with the progress of the treatment, and the resulting optical thin film In some cases, dispersibility, stability, and moldability in the coating composition are insufficient, and the obtained optical thin film has low transparency, high haze, and insufficient light collecting properties.

For the mechanochemical treatment method of the present invention, a conventionally known method can be adopted except that the above-described inorganic oxide particles, coating resin, organic solvent, mixing ratio and concentration are adopted.
For example, a predetermined amount of an organic solvent, inorganic oxide particles, and resin coating material are weighed in a Henschel mixer, a homomixer, a homogenizer, a bead mill, etc., and stirred at a high speed.

  The stirring speed varies depending on the apparatus and method used, but if it is too slow, if the particle size of the inorganic oxide particles is large, the agglomeration or pulverization becomes insufficient, and the resulting resin-coated inorganic oxide particle particles The diameter may be too large, the amount of resin coating may be insufficient, or the bonding between the particles and the resin may be insufficient, or the stability and moldability of the optical thin film forming paint may be insufficient. The resulting optical thin film may be insufficient in transparency, haze, light collecting property, hardness, scratch resistance and the like.

  Conventionally, when a resin is coated by the method described above, a polymerization initiator is added, or ultraviolet irradiation or plasma irradiation is performed. However, when a polymerization initiator is added or ultraviolet irradiation is performed, a coating resin is used. Does not cover the particle surface, or even if the resin is coated, the polymerization and curing of the resin proceeds so much that the (meth) acrylate resin (A) not having a fluorene skeleton (A), the (meth) acrylate resin having a fluorene skeleton ( There is a tendency that the affinity and binding properties with B) are lowered, and the transparency, light transmittance, hardness, scratch resistance and the like of the optical thin film are lowered.

The average particle diameter of the resin-coated inorganic oxide particles (C) thus obtained is preferably 5 to 50 nm, more preferably 8 to 40 nm.
Although the resin coating amount is in the above range, the average particle diameter of the inorganic oxide particles before and after the resin coating may be substantially the same, and the average particle diameter after the resin coating may naturally be large. . When the average particle diameter of the obtained particles is within the above range, a transparent film excellent in transparency, haze, light transmittance, hardness, scratch resistance and light collecting property can be obtained.

In the present invention, the average particle diameter of the resin-coated inorganic oxide particles (C) was determined by a transmission electron micrograph (TEM) observation method.
The end point of the mechanochemical treatment is not particularly limited as long as the resin-coated inorganic oxide particles (C) can be obtained, and a part of the unreacted resin (not involved in coating) may remain.

Method for Producing Optical Thin Film Forming Paint Next, in the optical thin film forming paint according to the present invention, a (meth) acrylate resin is mixed with the resin-coated inorganic oxide particles (C) obtained by the above production method. Specifically, when preparing the resin-coated inorganic oxide particles (C), the (meth) acrylate resin (A) and the fluorene having no fluorene skeleton so as to have a predetermined ratio after the mechanical treatment. The (meth) acrylate resin (B) having a skeleton and an organic solvent are mixed, and then the contained organic solvent is removed.

  After mixing the (meth) acrylate-based resin (A) having no fluorene skeleton and the (meth) acrylate resin (B) having a fluorene skeleton, the components may be stirred so that they are uniformly dispersed. If necessary, the mechanochemical treatment can be continued.

  The method for removing the organic solvent varies depending on the type, boiling point, blending amount, etc. of the organic solvent, but is performed under heating, preferably under heating and reduced pressure. The heating temperature varies depending on the resin, but is lower than the temperature at which the polymerization of the resin starts, and is usually preferably 50 ° C. or lower. As the apparatus, a rotary evaporator, a vacuum distillation apparatus or the like is employed.

It is preferable to remove the organic solvent until the remaining amount of the organic solvent in the resulting optical thin film-forming coating material is 1000 ppm or less, more preferably 500 ppm or less.
If a large amount of organic solvent remains in the optical thin film forming paint, the viscosity of the optical thin film forming paint will be low, but it is necessary to provide a drying step during the formation of the optical thin film to remove the organic solvent. In some cases, the effect of improving the denseness, hardness, scratch resistance and the like of the film cannot be sufficiently obtained. In addition, the residual organic solvent causes a large shrinkage of the film during curing, which may greatly reduce the moldability.

  The viscosity of the coating for forming an optical thin film prepared as described above is in the range of 10 to 8,000 mPa · s, preferably 50 to 5,000 mPa · s, more preferably 100 to 3,000 mPa · s. preferable. If it exists in this range, it is excellent in coating property, handling property, optical thin film formation property, etc.

Furthermore, a polymerization initiator or a curing agent can be mixed in the coating for forming an optical thin film, if necessary. Specifically, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethyl-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-hydroxy-methyl-2 -Methyl-phenyl-propane-1-ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1- [4- (methylthio) Phenyl] -2-morpholinopropan-1-one and the like. These contents are desirably in the range of 2 to 20% by weight, preferably 4 to 16% by weight, based on the weight of the resin.
Next, the optical thin film according to the present invention will be described.

Optical thin film The optical thin film according to the present invention is formed by using the optical thin film forming paint described above.

  Specifically, the coating material for forming an optical thin film described above is a base material or a templating agent by a known method such as dipping, spraying, spinner, roll coating, bar coating, gravure printing, or micro gravure printing. An optical thin film can be formed by applying the resin onto the substrate and curing it by an ordinary method such as ultraviolet irradiation or heat treatment.

The shape and size of the optical thin film vary depending on applications such as a sealing material for a light emitting diode, a prism sheet for a liquid crystal display device, and a hard coat film.
For example, a transparent film having a constant film thickness, a transparent film in which a plurality of transparent films having a constant film thickness and a different refractive index are laminated, a prism sheet-like thin film in which triangular prisms are connected in parallel, and an upper surface having a convex structure (convex lens shape) or Examples thereof include a film having a concavo-convex structure (wave structure), and a film having a number of convex structures on the upper surface.

  Examples of use of such optical thin films are shown in FIGS. FIG. 1 shows an example in which the optical thin film of the present invention is applied to an LED prism sheet. FIG. 2 is an example in which the optical thin film of the present invention is applied in the descending order of refractive index as an LED sealing material. FIG. 3 shows an example in which the thick optical thin film of the present invention is applied as an LED sealing material.

The thickness of the optical thin film is not particularly limited and is appropriately selected according to the shape. Usually, it is in the range of 0.01 to 10 mm, and further 0.02 to 8 mm. Further, when forming a wave-like, prism-like or lens-like thin film, the maximum thickness may be in the above range. When the thickness is within this range, the film hardness and scratch resistance are high, and the thin film does not crack or curl (curve or warp).
The light transmittance of the optical thin film is preferably 80% or more, and more preferably 85% or more.

  In the present invention, the light transmittance of the optical thin film is the light transmittance when a thin film having a thickness of 70 μm is formed. If the light transmittance of the optical thin film is low, for example, when used as a sealing material for an LED, the energy emitted from the LED is stored as thermal energy and becomes high temperature, so the sealing resin turns yellow and the brightness of the LED May decrease.

Moreover, it is preferable that the refractive index of an optical thin film exists in the range of 1.6-1.8, Furthermore, 1.7-1.8.
An optical thin film having a refractive index in this range has insufficient light collecting properties. For example, when used as an LED sealing material, yellowing of the sealing resin due to heat storage as described above is also suppressed. The brightness of can be kept high. Since it has a predetermined refractive index, reflection by the sealing material is also suppressed.

  The optical thin film has, as one aspect, a thin film whose upper surface is a single convex surface, a thin film whose upper surface is a large number of convex surfaces, a thin film whose upper surface is uneven (wavy), and a prism sheet in which triangular prisms are connected in parallel. It may be a thin film.

  The coating composition for forming an optical thin film of the present invention does not contain a solvent. Therefore, a drying process for removing the solvent is unnecessary, and shrinkage due to the solvent removal does not occur. Therefore, a prism sheet or the like is formed in the same shape and size as the mold. can do. Therefore, the coating material for forming an optical thin film of the present invention can be used for LED sealing materials, prism sheets, prisms, and convex lenses of optical materials.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited by these Examples.

[Example 1]
Preparation of inorganic oxide particles (1 ) 35 g of zirconium oxychloride octahydrate (ZrOCl ₂ .8H ₂ O (manufactured by Taiyo Mining Co., Ltd .: ZrO ₂ concentration 37.2 wt%)) was dissolved in 1,300 g of pure water. A zirconium hydroxide hydrogel (ZrO ₂ concentration 1% by weight) was prepared by adding 123 g of a 10% by weight aqueous KOH solution, and the conductivity was reduced to 0.5 mS / cm or less by the ultrafiltration membrane method. Washed until

After adding 400 g of 10 wt% KOH aqueous solution to 2,000 g of 1 wt% zirconium hydroxide hydrogel as the obtained ZrO ₂ , 200 g of 35 wt% hydrogen peroxide aqueous solution and 35 g of tartaric acid were added. added. At this time, the solution foamed vigorously and the solution became transparent, and the pH was 11.5.

  This solution is filled in an autoclave, hydrothermally treated at 150 ° C. for 11 hours, then taken out, concentrated to 10% using an ultrafiltration membrane, and the conductivity is 0.2 mS / cm or less with pure water. Until washed. Subsequently, it was made into the dispersion liquid of 20 weight% of solid content concentration, and it sprayed in the hot air with an inlet temperature of 400 degreeC, and prepared the spray-dried inorganic oxide particle (1). At this time, the outlet temperature was 150 ° C.

Subsequently, it heat-processed with 105 degreeC and 20 hours with the dryer, and prepared the inorganic oxide particle (1) powder which consists of zirconia.
The average primary particle diameter of the inorganic oxide particles (1) was 15 nm, the average secondary particle diameter was 10 μm, and the crystal form was monoclinic as measured by X-ray diffraction. The refractive index was 2.20.

Resin-coated inorganic oxide particles (1) Preparation of organic solvent dispersion liquid Next, inorganic oxide particles (1) powder 125.45 g, propylene glycol monomethyl ether (PGME) 232.999 g as an organic solvent, phenol novolac type as a coating resin 105.06 g of epoxy acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK Oligo EA-6320 / PGMAC, solid content concentration 80%) and 1713.6 g of zirconia beads (diameter 0.05 mm), bead mill (Kampe Co., Ltd.) : BATCH SAND), disperse, adjust the concentration with PGME solvent, inorganic oxide particles (1) solid content concentration 20 wt%, total solid content concentration (inorganic oxide particles (1) + resin) 33.4% by weight of resin-coated inorganic oxide particles (1) An organic solvent dispersion was prepared. The weight ratio of the inorganic oxide fine particles (1) to the coating resin was 60/40.
The average particle diameter and refractive index of the resin-coated inorganic oxide particles (1) were measured, and the results are shown in Table 1. The average particle size was measured with a laser particle size analysis system (Otsuka Electronics: FPAR-1000).

Preparation of Optical Thin Film Forming Paint (1) Resin-coated inorganic oxide particles (1) Phenoxypolyethylene glycol acrylate (Shin Nakamura Chemical Co., Ltd.) as (meth) acrylate resin (A) having no fluorene skeleton in 100 g of organic solvent dispersion KK ester: AMP ester AMP-20GY, molecular weight: 236) After adding 12 g and stirring sufficiently, fluorene acrylate (manufactured by Osaka Gas Chemical Co., Ltd .: as (meth) acrylate resin (B) having a fluorene skeleton) 22.5 g of Ogsol EA-0200) was added.

Subsequently, with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the temperature of the warm bath was increased to 60 ° C., the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (1).
At this time, the weight ratio of the resin-coated inorganic oxide particles (1) (ZrO ₂ + coated resin) to the (meth) acrylate-based resin (A) and (meth) acrylate-based resin (B) ((1) / (A ) / (B)) was 49.2 / 17.7 / 33.1. Moreover, (C _F ) / (C _R ) was 1.87.
The remaining amount and stability of the organic solvent, viscosity, and refractive index of the obtained optical thin film forming paint (1) were measured, and the results are shown in Table 1. The stability, viscosity, and refractive index were evaluated by the following methods and evaluation criteria.

Stability Evaluation The optical thin film-forming coating material (1) was filled in a transparent container and allowed to stand, and the state of precipitated particles was observed at the bottom of the container, and evaluated according to the following criteria. The results are shown in Table 1.
No sedimentation layer of particles was observed for more than 1 week. : ◎
A sedimentation layer of particles was observed in 3 to 6 days. : ○
A sedimentation layer of particles was observed in 1 to 2 days. : △
Within 1 day, a sedimentation layer of particles was observed. : ×

The liquid temperature of the viscosity optical thin film-forming coating material (1) was adjusted to 25 ° C. and measured with an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd .: EHD type).

The liquid temperature of the refractive index optical thin film-forming coating material (1) was set to 25 ° C. and measured with an Abbe refractometer (manufactured by Atago Co., Ltd .: NAR-3T type).

Manufacture of optical thin film (1) 66.8 g of optical thin film forming paint (1) was mixed with 2.7 g of 1-hydroxy-cyclohexyl-phenyl ketone (BASF Co., Ltd .: Irgacure 184) as a photoinitiator. An optical thin film forming paint (1) to which an initiator was added was prepared.

An optical thin film-forming paint (1) to which a photoinitiator was added was applied to an easily adhesive PET film (Toyobo Co., Ltd .: Cosmo Shine A-4300, thickness: 188 μm, refractive index: 1.65, total light transmittance 91. 0%, haze 0.8%) by a bar coater method (bar # 40) and 1200 mJ / with an ultraviolet irradiation device (manufactured by Nihon Battery: UV irradiation device CS30L21-3) equipped with a high-pressure mercury lamp (120 W / cm). Irradiation was cured under conditions of cm ² to prepare a substrate with an optical thin film (1). At this time, the thickness of the optical thin film (1) was 70 μm.

  The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (1) were measured, and the results are shown in Table 1. The total light transmittance and haze were measured with a haze meter (NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd.), and the results are shown in Table 1. Further, pencil hardness, scratch resistance and adhesion were evaluated by the following methods and evaluation criteria, and the results are shown in Table 1.

Measurement of pencil hardness It measured with the pencil hardness tester according to JIS-K-5600.

Measurement of Scratch Resistance Using # 0000 steel wool, sliding 50 times at a load of 250 g / cm ² , visually observing the surface of the film and evaluating it according to the following criteria, the results are shown in Table 1.
Evaluation criteria:
No streak injury is found: ◎
Slightly scratched streak: ○
Many scratches are found in the streak: △
The surface has been cut entirely: ×

Refractive index of coating film In place of the above PET film substrate, an optical thin film forming coating (1) with a photoinitiator added on a silicon wafer is applied and cured in the same manner to form a coating film having a thickness of 50 μm. The refractive index was measured with a meter (manufactured by SOPRA: ESVG), and the results are shown in Table 1.

[Example 2]
Preparation of Optical Thin Film Forming Paint (2) Resin-coated inorganic oxide particles prepared in the same manner as in Example 1 (1) 100 g of organic solvent dispersion (meth) acrylate resin (A) having no fluorene skeleton 9.3 g of phenoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK ester AMP-20GY, molecular weight: 206), and after sufficiently stirring, (meth) acrylate resin (B) having a fluorene skeleton 47.1 g of fluorene acrylate (manufactured by Osaka Gas Chemical Co., Ltd .: Ogsol EA-0200) was added.
Subsequently, the temperature of the warm bath was changed to 60 ° C. with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (2).

The weight ratio of the resin-coated inorganic oxide particles (1) and the (meth) acrylate resins (A) and (B) in the paint was 31.6 / 23.8 / 44.6. Moreover, (C _F ) / (C _R ) was 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film-forming paint (2) were measured, and the results are shown in Table 1.

Production of optical thin film (2) A substrate with an optical thin film (2) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (2) was used. At this time, the thickness of the optical thin film (2) was 70 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (2) were measured, and the results are shown in Table 1.

[Example 3]
Preparation of Optical Thin Film Forming Paint (3) Resin-coated inorganic oxide particles prepared in the same manner as in Example 1 (1) 100 g of organic solvent dispersion (meth) acrylate resin (A) having no fluorene skeleton 9.3 g of phenoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK ester AMP-20GY, molecular weight: 236), and after sufficiently stirring, (meth) acrylate resin (B) having a fluorene skeleton 17.5 g of fluorene acrylate (manufactured by Osaka Gas Chemical Co., Ltd .: Ogsol EA-0200) was added.

Subsequently, with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the temperature of the warm bath was changed to 60 ° C., the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (3).
The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate resins (A) and (B) in the paint is 55.5 / 15.5 / 29. Further, (C _F ) / (C _R ) is 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film-forming paint (3) were measured, and the results are shown in Table 1.

Production of optical thin film (3) A substrate with an optical thin film (3) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (3) was used. At this time, the thickness of the optical thin film (3) was 90 μm. The total optical transmittance, haze, scratch resistance and refractive index of the obtained optical thin film (3) were measured, and the results are shown in Table 1.

[Example 4]
Preparation of Optical Thin Film Forming Paint (4) Resin-coated inorganic oxide particles prepared in the same manner as in Example 1 (1) 100 g of organic solvent dispersion (meth) acrylate resin (A) having no fluorene skeleton As a (meth) acrylate resin (B) having a fluorene skeleton after adding 11.1 g of phenoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK ester AMP-20GY, molecular weight: 236) and stirring sufficiently 23.4 g of fluorene acrylate (manufactured by Osaka Gas Chemical Co., Ltd .: Ogsol EA-0200) was added.
Subsequently, with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the temperature of the warm bath was changed to 60 ° C., the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (4).

The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate-based resins (A) and (B) in the paint is 49.2 / 16.4 / 34.4. Further, (C _F ) / (C _R ) is 2.1.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film-forming paint (4) were measured, and the results are shown in Table 1.

Production of optical thin film (4) In Example 1, a substrate with an optical thin film (4) was prepared in the same manner except that the coating for forming an optical thin film (4) was used. At this time, the thickness of the optical thin film (4) was 70 μm.
The optical thin film (4) obtained was measured for total light transmittance, haze, scratch resistance, and refractive index, and the results are shown in Table 1.

[Example 5]
Preparation of Optical Thin Film Forming Paint (4) Resin-coated inorganic oxide particles prepared in the same manner as in Example 1 (1) 100 g of organic solvent dispersion (meth) acrylate resin (A) having no fluorene skeleton After adding 17.2 g of phenoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK ester AMP-20GY, molecular weight: 236) and stirring sufficiently, (meth) acrylate resin (B) having a fluorene skeleton is added. 17.2 g of fluorene acrylate (manufactured by Osaka Gas Chemical Co., Ltd .: Ogsol EA-0200) was added.
Subsequently, with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the temperature of the warm bath was changed to 60 ° C., the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (4).

The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate resins (A) and (B) in the paint is 49.2 / 25.4 / 25.4. Further, (C _F ) / (C _R ) is 1.0.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film-forming paint (5) were measured, and the results are shown in Table 1.

Production of optical thin film (5) In Example 1, a substrate with an optical thin film (5) was prepared in the same manner except that the coating for forming an optical thin film (5) was used. The thickness of the optical thin film (5) at this time was 70 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (5) were measured, and the results are shown in Table 1.

[Example 6]
Preparation of Optical Thin Film Forming Paint (6) In Example 1, phenoxyethyl methacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK ester PHE-1G, molecular weight) as (meth) acrylate resin (A) having no fluorene skeleton 206) A coating material for forming an optical thin film (6) was prepared in the same manner except that 12 g was added.

The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.

Production of optical thin film (6) A substrate with an optical thin film (6) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (6) was used. At this time, the thickness of the optical thin film (6) was 70 μm. The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (6) were measured, and the results are shown in Table 1.

[Example 7]
Preparation of Optical Thin Film Forming Paint (7) In Example 1, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate (manufactured by Kyoeisha Chemical Co., Ltd.) as the (meth) acrylate resin (A) having no fluorene skeleton : Light ester HO-MPP, molecular weight: 336) A coating for optical thin film formation (7) was prepared in the same manner except that 12 g was added.

The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate-based resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.

Production of optical thin film (7) A substrate with an optical thin film (7) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (7) was used. The thickness of the optical thin film (7) at this time was 70 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (7) were measured, and the results are shown in Table 1.

[Example 8]
Preparation of inorganic oxide particles (2) In Example 1, after filling in an autoclave and hydrothermally treating at 150 ° C. for 11 hours, it was taken out, concentrated to 10% using an ultrafiltration membrane, and then purified water. Washing was performed until the electrical conductivity was 0.2 mS / cm or less. Then, after drying with a dryer at 105 ° C. for 20 hours, the mixture was pulverized with a mortar and then sieved with a 44 μm wire mesh to prepare inorganic oxide particle (2) powder composed of zirconia.
The average primary particle diameter of the inorganic oxide particles (2) was 15 nm, the average secondary particle diameter was 35 μm, and the crystal form was monoclinic as measured by X-ray diffraction. The refractive index was 2.20.

Preparation of Resin Coated Inorganic Oxide Particles (2) Organic Solvent Dispersion In Example 1, the solid content concentration of inorganic oxide particles (2) was the same as in Example 1, except that 125.45 g of inorganic oxide particles (2) was used. A resin-coated inorganic oxide particle (2) organic solvent dispersion of 20% by weight and a total solid content (inorganic oxide particle (1) + resin) of 33.4% by weight was prepared.
The average particle diameter and refractive index of the resin-coated inorganic oxide particles (1) were measured, and the results are shown in Table 1.

Preparation of Optical Thin Film Forming Paint (8) An optical thin film forming paint (8) was prepared in the same manner as in Example 1 except that the resin-coated inorganic oxide particles (2) were used.

The weight ratio of the resin-coated inorganic oxide particles (2) to the (meth) acrylate resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (8) were measured, and the results are shown in Table 1.

Production of optical thin film (8) A substrate with an optical thin film (8) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (8) was used. The thickness of the optical thin film (8) at this time was 70 μm.
The optical thin film (8) thus obtained was measured for total light transmittance, haze, scratch resistance, and refractive index, and the results are shown in Table 1.

[Example 9]
Preparation of Resin-Coated Inorganic Oxide Particles (3) Organic Solvent Dispersion In Example 1, 125.45 g of inorganic oxide particles (1 ) powder, 232.99 g of propylene glycol monomethyl ether (PGME) as an organic solvent, and as a coating resin 67.2 g of phenol novolac epoxy acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK Oligo EA-6320 / PGMAC, solid content concentration 80%) and 1713.6 g of zirconia beads (diameter 0.05 mm) were mixed with a bead mill (campe ( Co., Ltd .: BATCH SAND), dispersed and adjusted with a PGME solvent, the solid content concentration of inorganic oxide particles (1) is 20% by weight, the total solid content concentration (inorganic oxide particles (1) + Resin) 28.6 wt% of resin-coated inorganic oxide particles (3) An organic solvent dispersion was prepared. The weight ratio of the inorganic oxide fine particles (1) to the coating resin was 70/30.
The average particle diameter and refractive index of the resin-coated inorganic oxide particles (3) were measured, and the results are shown in Table 1.

Preparation of coating material for forming optical thin film (9) Resin-coated inorganic oxide particles (3) In 100 g of organic solvent dispersion, phenoxypolyethylene glycol acrylate (Shin-Nakamura Chemical Co., Ltd.) as (meth) acrylate resin (A) having no fluorene skeleton KK ester: NK ester AMP-20GY, molecular weight: 236) 10.3 g was added and stirred sufficiently, and then fluorene acrylate (Osaka Gas Chemical Co., Ltd.) was used as (meth) acrylate resin (B) having a fluorene skeleton. 19.2 g): manufactured by Ogsol EA-0200).

Subsequently, the temperature of the warm bath was changed to 60 ° C. with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (9).
The weight ratio of the resin-coated inorganic oxide particles (3) and the (meth) acrylate-based resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (9) were measured, and the results are shown in Table 1.

Production of optical thin film (9) A substrate with an optical thin film (9) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (9) was used. The thickness of the optical thin film (9) at this time was 70 μm.
The optical thin film (9) obtained was measured for total light transmittance, haze, scratch resistance, and refractive index, and the results are shown in Table 1.

[Example 10]
Preparation of Resin Coated Inorganic Oxide Particles (4) Organic Solvent Dispersion In Example 1, 125.45 g of the inorganic oxide particle (1) powder, 232.99 g of acetone as the organic solvent, and a phenol novolac epoxy acrylate (as the coating resin) Shin Nakamura Chemical Co., Ltd .: NK Oligo EA-6320 / PGMAC, solid content concentration 80%) 156.8 g and zirconia beads (diameter 0.05 mm) 1713.6 g, beads mill (Kampe Co., Ltd. product: BATCH SAND) ), The concentration is adjusted with a PGME solvent, the solid content concentration of the inorganic oxide particles (1) is 20% by weight, the total solid content concentration (inorganic oxide particles (1) + resin) is 40% by weight. Resin-coated inorganic oxide particles (4) An organic solvent dispersion was prepared. The weight ratio of the inorganic oxide fine particles (1) to the coating resin was 50/50.
The average particle diameter and refractive index of the resin-coated inorganic oxide particles (4) were measured, and the results are shown in Table 1.

Preparation of Optical Thin Film Forming Paint (10) An optical thin film forming paint (10) was prepared in the same manner as in Example 1 except that the resin-coated inorganic oxide particles (4) were used.

The weight ratio of the resin-coated inorganic oxide particles (4) and the (meth) acrylate resins (A) and (B) in the paint is 50/18/32. Further, (C _F ) / (C _R ) is 1.8. The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (10) were measured, and the results are shown in Table 1.

Production of optical thin film (10) A substrate with an optical thin film (10) was prepared in the same manner as in Example 1 except that the coating material for forming an optical thin film (10) was used. The thickness of the optical thin film (10) at this time was 70 μm. The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (10) were measured, and the results are shown in Table 1.

[Example 11]
Preparation of optical thin film-forming coating material (11) In Example 1, the temperature of the warm bath was changed to 55 ° C. with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the degree of vacuum was gradually increased, and the solvent was removed in 2 hours. A thin film-forming paint (12) was prepared.

The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate-based resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87. The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (11) were measured, and the results are shown in Table 1.

Production of optical thin film (11) A substrate with an optical thin film (11) was prepared in the same manner as in Example 1 except that the coating material for forming an optical thin film (11) was used. At this time, the thickness of the optical thin film (11) was 30 μm. The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (12) were measured, and the results are shown in Table 1.

[Comparative Example 1]
Preparation of paint for optical thin film formation (R1) Resin-coated inorganic oxide particles (1) In 100 g of organic solvent dispersion, phenoxypolyethylene glycol acrylate (Shin-Nakamura Chemical Co., Ltd.) as (meth) acrylate resin (A) having no fluorene skeleton Co., Ltd .: NK ester AMP-20GY, molecular weight: 236) 34.5 g was added and sufficiently stirred.

Next, a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.) was used to set the temperature of the warm bath to 60 ° C., gradually increasing the degree of vacuum and removing the solvent in 2 hours to prepare an optical thin film forming paint (R1).
The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate resins (A) and (B) in the paint is 49.2 / 50.8 / 0. Further, (C _F ) / (C _R ) is zero.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (R1) were measured, and the results are shown in Table 1.

Production of Optical Thin Film (R1) A substrate with an optical thin film (R1) was prepared in the same manner as in Example 1 except that the optical thin film forming paint (R1) was used. At this time, the thickness of the optical thin film (R1) was 70 μm. The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (R1) were measured, and the results are shown in Table 1.

[Comparative Example 2]
Preparation of paint for forming optical thin film (R2) Resin-coated inorganic oxide particles (1) In 100 g of organic solvent dispersion, fluorene acrylate (made by Osaka Gas Chemical Co., Ltd.) as (meth) acrylate resin (B) having a fluorene skeleton : Ogsol EA-0200) 34.5 g was added and stirred thoroughly.

Next, a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.) was used to set the temperature of the warm bath to 60 ° C., gradually increasing the degree of vacuum and removing the solvent in 2 hours to prepare an optical thin film forming paint (R2).
The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate resins (A) and (B) in the paint is 49.2 / 0 / 50.8.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film-forming paint (R2) were measured, and the results are shown in Table 1.

Production of optical thin film (R2) A substrate with an optical thin film (R2) was prepared in the same manner as in Example 1 except that the coating material for forming an optical thin film (R2) was used. At this time, the thickness of the optical thin film (R2) was 150 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (R2) were measured, and the results are shown in Table 1.

[Comparative Example 3]
Preparation of inorganic oxide particles (R1 ) 35 g of zirconium oxychloride octahydrate (ZrOCl ₂ .8H ₂ O (manufactured by Taiyo Mining Co., Ltd .: ZrO ₂ concentration 37.2 wt%)) was dissolved in 1,300 g of pure water. A zirconium hydroxide hydrogel (ZrO ₂ concentration 1% by weight) was prepared by adding 123 g of a 10% by weight aqueous KOH solution, and the conductivity was reduced to 0.5 mS / cm or less by the ultrafiltration membrane method. Washed until

After adding 400 g of 10 wt% aqueous KOH solution to 2,000 g of 1 wt% zirconium hydroxide hydrogel as ZrO ₂ obtained, 200 g of hydrogen peroxide aqueous solution of 35 wt% and 10 g of tartaric acid were added. added. At this time, the solution foamed vigorously and the solution became transparent, and the pH was 11.5.

  This solution is filled in an autoclave, hydrothermally treated at 150 ° C. for 11 hours, then taken out, concentrated to 10% using an ultrafiltration membrane, and the conductivity is 0.2 mS / cm or less with pure water. Until washed. Next, a dispersion having a solid content concentration of 20% by weight was sprayed into hot air having an inlet temperature of 400 ° C. to prepare spray-dried inorganic oxide particles (R1). At this time, the outlet temperature was 150 ° C.

Subsequently, it heat-processed with 105 degreeC and 20 hours with the dryer, and prepared the inorganic oxide particle (R1) powder which consists of zirconia.
The average primary particle diameter of the inorganic oxide particles (R1) was 60 nm, the average secondary particle diameter was 15 μm, and the crystal form was monoclinic as measured by X-ray diffraction. The refractive index was 2.20.

Preparation of Resin-Coated Inorganic Oxide Particles (R1) Organic Solvent Dispersion Next, 125.45 g of inorganic oxide particles (R1) powder, 232.99 g of propylene glycol monomethyl ether (PGME) as an organic solvent, and phenol novolac type as a coating resin 105.06 g of epoxy acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK Oligo EA-6320 / PGMAC, solid content concentration 80%) and 1713.6 g of zirconia beads (diameter 0.05 mm), bead mill (Kampe Co., Ltd.) : BATCH SAND), disperse, adjust the concentration with PGME solvent, solid content concentration of inorganic oxide particles (R2) 20 wt%, total solid content concentration (inorganic oxide particles (R1) + resin) 33.4% by weight of resin-coated inorganic oxide particles (R1) in an organic solvent dispersion was prepared. The weight ratio of the inorganic oxide fine particles (R1) to the coating resin was 60/40.
The average particle diameter of the resin-coated inorganic oxide particles (R1) was measured, and the results are shown in Table 1.

Preparation of Optical Thin Film Forming Paint (R3) In Example 1, the same procedure was used for forming an optical thin film except that a resin-coated inorganic oxide particle (R1) organic solvent dispersion having a total solid concentration of 33.4% by weight was used. A paint (R3) was prepared.

The weight ratio of the resin-coated inorganic oxide particles (R1) to the (meth) acrylate resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film-forming paint (R3) were measured, and the results are shown in Table 1.

Production of optical thin film (R3) A substrate with an optical thin film (R4) was prepared in the same manner as in Example 1 except that the coating material for forming an optical thin film (R4) was used. The thickness of the optical thin film (R4) at this time was 120 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (R3) were measured, and the results are shown in Table 1.

[Example 12]
Preparation of Optical Thin Film Forming Paint (12) Resin-coated inorganic oxide particles (1) prepared in the same manner as in Example 1 (Meth) acrylate resin (A) having no fluorene skeleton in 100 g of organic solvent dispersion After adding 12 g of methyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd .: molecular weight: 86) and stirring sufficiently, fluorene acrylate (Osaka Gas Chemical Co., Ltd.) was used as the (meth) acrylate resin (B) having a fluorene skeleton. ): Ogsol EA-0200) 22.5 g was added.

Subsequently, the temperature of the warm bath was set to 60 ° C. with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (12).
The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate-based resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (12) were measured, and the results are shown in Table 1.

Production of Optical Thin Film (12) A substrate with an optical thin film (12) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (12) was used. The thickness of the optical thin film (12) at this time was 70 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (12) were measured, and the results are shown in Table 1.

[Comparative Example 4]
Preparation of paint for forming optical thin film (R5) Resin-coated inorganic oxide particles prepared in the same manner as in Example 1 (1) 100 g of organic solvent dispersion (meth) acrylate resin (A) having no fluorene skeleton After adding 12 g of polyglycerin polyethylene glycol polyacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK ECONOMER A-PG5054E, molecular weight: 3400) and stirring sufficiently, (meth) acrylate resin (B) having a fluorene skeleton is added. 22.5 g of fluorene acrylate (manufactured by Osaka Gas Chemical Co., Ltd .: Ogsol EA-0200) was added.
Subsequently, the temperature of the warm bath was set to 60 ° C. with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (R5).

The weight ratio of the resin-coated inorganic oxide particles (1) to the (meth) acrylate-based resins (A) and (B) in the paint is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film-forming paint (R5) were measured, and the results are shown in Table 1.

Production of optical thin film (R5) A substrate with an optical thin film (R5) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (R5) was used. The thickness of the optical thin film (R5) at this time was 130 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (R5) were measured, and the results are shown in Table 1.

[Example 13]
Preparation of inorganic oxide particles (13) 13 g of ammonium nitrate and 20 g of 15% ammonia water were added to 8060 g of pure water and stirred, and the temperature was raised to 50 ° C. A solution obtained by dissolving 1519 g of potassium stannate in 4290 g of pure water was added with a roller pump over 10 hours. At this time, nitric acid having a concentration of 10% by weight was added and adjusted so as to maintain the pH at 8.8 with a pH controller. After the addition was completed, the temperature was kept at 50 ° C. for 1 hour, and then 10% by weight nitric acid was added to lower the pH to 3.0. Next, it was washed with pure water until the filtered water conductivity reached 10 μS / cm with an ultrafiltration membrane, and then concentrated with an ultrafiltration membrane. The amount of liquid taken out at this time was 6000 g, and the solid content (SnO ₂ ) concentration was 12% by weight. To this slurry, 264 g of a phosphoric acid aqueous solution having a concentration of 16% by weight was added and stirred for 0.5 hour.

  This was dried at 105 ° C. for 2 hours and then calcined at 700 ° C. for 2 hours to prepare inorganic oxide particle (13) powder made of P-doped tin oxide (PTO). The average primary particle diameter of the inorganic oxide particle (13) powder was 15 nm, the average secondary particle diameter was 0.45 μm, and the volume resistance value was 5000 Ω · cm. The refractive index was 1.90.

Preparation of Resin-Coated Inorganic Oxide Particles (13) Organic Solvent Dispersion Next, 125.45 g of inorganic oxide particles (13) powder, 232.99 g of propylene glycol monomethyl ether (PGME) as an organic solvent, and phenol novolac type as a coating resin 67.2 g of epoxy acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK Oligo EA-6320 / PGMAC, solid content concentration 80%) and 1713.6 g of zirconia beads (diameter 0.05 mm), bead mill (manufactured by Campe Co., Ltd.) : BATCH SAND), disperse, adjust the concentration with PGME solvent, solid content concentration of inorganic oxide particles (13) 20% by weight, total solid content concentration (inorganic oxide particles (13) + resin) 28.6% by weight of resin-coated inorganic oxide particles (13) An organic solvent dispersion was prepared. The weight ratio of the inorganic oxide fine particles (13) to the coating resin was 70/30.
The average particle diameter and refractive index of the resin-coated inorganic oxide particles (13) were measured, and the results are shown in Table 1.

Preparation of coating material for optical thin film formation (13) Resin-coated inorganic oxide particles (13) Phenoxypolyethylene glycol acrylate (Shin Nakamura Chemical Co., Ltd.) as a (meth) acrylate resin (A) having no fluorene skeleton in 100 g of organic solvent dispersion KK ester: NK ester AMP-20GY, molecular weight: 236) 10.3 g was added and stirred well, then fluorene acrylate (Osaka Gas Chemical Co., Ltd.) as a (meth) acrylate resin (B) having a fluorene skeleton. 19.2 g of Ogsol EA-0200).

Subsequently, with a rotary evaporator (manufactured by Shibata Chemical Co., Ltd.), the temperature of the warm bath was increased to 60 ° C., the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare an optical thin film forming paint (13).
At this time, the weight of the resin-coated inorganic oxide particles (13) (PTO + coated resin), the (meth) acrylate resin (A) not having a fluorene skeleton, and the (meth) acrylate resin (B) having a fluorene skeleton The ratio ((13) / (A) / (B)) is 49.2 / 17.7 / 33.1. Further, (C _F ) / (C _R ) is 1.87.
The remaining amount and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (13) were measured, and the results are shown in Table 1.

Production of optical thin film (13) A substrate with an optical thin film (13) was prepared in the same manner as in Example 1 except that the coating for forming an optical thin film (13) was used. At this time, the thickness of the optical thin film (13) was 70 μm. The total optical transmittance, haze, pencil hardness, scratch resistance, and refractive index of the obtained optical thin film (13) were measured, and the results are shown in Table 1.

[Reference Example 14]
Preparation of Optical Thin Film Forming Paint (14) An optical thin film forming paint (1) was prepared in the same manner as in Example 1, and propylene glycol monomethyl ether (PGME) as an organic solvent was added to the paint at a concentration of 5% by weight. An optical thin film forming paint (14) was prepared.
The concentration and stability of the organic solvent, the viscosity and the refractive index of the obtained optical thin film forming paint (14) were measured, and the results are shown in Table 1.

Production of optical thin film (14) A substrate with an optical thin film (14) was prepared in the same manner as in Example 1 except that the optical thin film forming paint (14) was applied and dried at 80 ° C for 5 minutes. The thickness of the optical thin film (14) at this time was 8 μm.
The total optical transmittance, haze, scratch resistance, and refractive index of the obtained optical thin film (12) were measured, and the results are shown in Table 1.

Claims (11)

A (meth) acrylate resin (A) having a fluorene skeleton having a weight average molecular weight of 86 to 3,000, and
(Meth) acrylate resin (B) having a fluorene skeleton,
The inorganic oxide fine particle is a (meth) acrylate resin having an aromatic ring selected from phenol novolac type epoxy acrylate and cresol novolac type epoxy acrylate , and the weight ratio of (particle / resin) is 97/3 to 20/80. Coated resin-coated inorganic oxide fine particles (C) having an average particle diameter in the range of 5 to 50 nm,
The concentration (C _R ) of the (meth) acrylate resin (A) not having the fluorene skeleton is in the range of 10 to 60% by weight as the solid content, and the (meth) acrylate resin (B) having the fluorene skeleton. The concentration (C _F ) of the resin is in the range of 10 to 60% by weight as the solid content, the concentration of the resin-coated inorganic oxide fine particles (C) is in the range of 20 to 70% by weight as the solid content, and the concentration of the organic solvent A coating for forming an optical thin film, characterized by having a water content of 800 ppm or less.   The paint for forming an optical thin film according to claim 1, wherein the (meth) acrylate-based resin (A) having no fluorene skeleton has an aromatic ring and / or an epoxy ring. Concentration ratio (C _F ) between the concentration (C _R ) of the (meth) acrylate resin (A) not having the fluorene skeleton and the concentration (C _F ) of the (meth) acrylate resin (B) having the fluorene skeleton 3. The coating composition for forming an optical thin film according to claim 1, wherein / (C _R ) is in the range of 0.2 to 3.0.   The optical thin film-forming coating material according to any one of claims 1 to 3, wherein the resin-coated inorganic oxide fine particles (C) have a refractive index in the range of 1.7 to 2.1.   The coating material for forming an optical thin film according to any one of claims 1 to 4, wherein the inorganic oxide fine particles are zirconia-based fine particles.   6. The coating composition for forming an optical thin film according to claim 1, wherein the viscosity (η) is in the range of 10 to 8,000 Pa · s.   Refractive index exists in the range of 1.5-1.8, The coating material for optical thin film formation in any one of Claims 1-6 characterized by the above-mentioned.   An optical thin film formed using the optical thin film-forming paint according to claim 1.   The optical thin film according to claim 8, wherein the optical transmittance is 80% or more.   The optical thin film according to claim 8 or 9, wherein a refractive index is in a range of 1.6 to 1.8.   The optical thin film according to any one of claims 8 to 10, wherein a wave shape, a prism shape, a sawtooth shape, a convex lens shape, and a concave lens shape are provided.

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